As you can see, the 2 kits have different timings, voltages, and CLs. Is it possible use them together, either as is or by overclocking one somehow?
To use them how, at all or as dual-channel?
You can use them together in general because the faster one will simply be slowed down to match the speed of the slower one.
As for dual-channel, you should be able to do it as long as you keep each matched pair in a separate channel (refer to your motherboard manual for slot-channel assignments).